A small, sterile, threaded rod with a slotted head used for internal spinal fixation by being screwed into the spine to hold plates, or other stabilization device, to bone; it is made of a material that is not chemically degraded or absorbed via natural body processes (includes implant grade metal such as surgical steel, titanium alloy, or carbon fibre). The device is typically used to provide immobilization and stabilization of spinal segments in the treatment of various spinal instabilities or deformities.